Argh dreaded coolant leak

[Dakar Timm]

I finally finished the replacement floor pans . Only problem was when I fired it up to take the car off the ramps coolant ran “ quite freely “ from where it appears to be behind the timing chain ?
As far as I can see , it is not coming from the water pump or the intake manifold . I wiped both completely dry before firing up the car again . Is it possible that a gasket in the timing cover blew ? The motor is a 318 Polyhead if it makes any differance

 

[66 Sat]

Hard to tell from the photo - are you sure it's not from one of the waterpump/alternator bracket bolts? The fan can blow the stuff everywhere.

Dry it all off and then start the car and watch carefully.

 

[Don Frelier]

The timing cover is a common leak source.

 

[Dakar Timm]

It definitely is coming from behind the timing cover case . I will try to provide a better photo of the source .
It is very difficult to get a camera in where it leaks.
Where can I find an assembly diagram for this ?
Once again thank you

 

[copper67sat]

If you don't have a service manual, I recommend downloading it from MyMopar.com. https://www.mymopar.com/downloads/servicemanuals/1966_Dart_Coronet_Service_Manual.zip

I've never worked on a poly, but the LA and Magnum SBs are prone to leaking between the block and timing cover. If the timing set is old, I suggest replacing that while you're in there.

Good luck with the repair.

 

[Dakar Timm]

If you don't have a service manual, I recommend downloading it from MyMopar.com. https://www.mymopar.com/downloads/servicemanuals/1966_Dart_Coronet_Service_Manual.zip

I've never worked on a poly, but the LA and Magnum SBs are prone to leaking between the block and timing cover. If the timing set is old, I suggest replacing that while you're in there.

Good luck with the repair.

I have in my possession a Dodge Service manual . After looking through it I see passages through the timing housing . One from each head ,I'm assuming . Where would I be ordering replacement gaskets from ?

 

[pnora]

I have in my possession a Dodge Service manual . After looking through it I see passages through the timing housing . One from each head ,I'm assuming . Where would I be ordering replacement gaskets from ?

Timing cover does not seal to the heads.

 

[66 Sat]

This is what a poly looks like with the timing cover off - the same as an LA. Replacing it with the sump in place was a pain but doable. I'd replace the crankshaft oil seal while you are there.

 

[Dakar Timm]

66 Sat , I had incorrectly assumed the pair of bores on either side of the block were from the heads . Your photo shows they are in the block itself . I'm now even more convinced the leak is from the passenger side coolant passage . Is there a brand preferances for the gaskets ? I'm of the opinion that this is something I'd like to do only once .Thank you

 

[66 Sat]

I used Felpro, no issues.

 

[Don Frelier]

I would put a timing chain on it as well if I'm in there that far.
And a new seal on the timing cover.
I sand a crosshatch pattern on the balancer where the oil seal rides.
If there is a groove on the balancer then you should use the repair seal style which uses a thin sleeve that gets glued over the balancer accompanied by a slightly larger seal.

Just start at the radiator and work your way in.
It's not a tough job just a bunch of bolts.
You do need a puller for the balancer.

 

[matthon]

After you drain the coolant to prevent it from spilling into the oil pan, it will spill into the oil pan.

A few of the lower bolts on the cover go through to the water jackets and antifreeze will drain out when removed. So more antifreeze will spill into the oil pan.

I did this awhile back and filmed it, of course I meander around and get distracted, but eventually get it done.

 

[WileE]

Be sure it's not coming from the weep hole on the bottom of the water pump. Also, are the bolts sealed ?